Single thread barbed drive screw



Oct. '25, 1932. i J, ARENZ 1,885,028

*SINGLE THREAD BARBED DRIVE SCREW Filed May 22, 1931 FA; 1. F/GZ 55,4

INVENTOR' fim YZKENZ BY HIS ATTORNEY f Patented Oct. 25, 1932 UNITED, STATES PATENT- OFFICE JOHN A. ABENZ, OI MOUNT VERNON, NEW YORK, ASSIGNOB TO THE INTERNATIONAL SCREW COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE SINGLE THREAD BABBED DRIVE SCREW Application filed Kay 22,

This invention relates to single thread barbed drive screws and in particular to screws of the spike type which are essentially time-savers when applied to the heavier construction work.

The primary object of my invention is the provision of a single thread barbed drive screw which has a portion of its body exter-' nally threaded to render the screw capable of being removed from its'seated position by being turned out, and which has a leading edge at its lower end so that the screw when driven into place, will travel in a straight line and will not be deflected to one side or the other and which, further, will spread apart the fibers of the wood with as little damage thereto as possible so that the fibers will wedge themselves about the upper edges of the screw thread and be engaged thereby, thus resisting endwise movement of the'screw itself.

Another and further object of my invention is the provision of a screw having a barbed thread thereon of suitable pitch so that the screw may be turned out of position but may be driven into position much more quickly than it could be turned into position and which is adapted for use in the fastening of cross arms to telegraph poles, for use as railway spikes and the like and which preferably is adapted to be driven into position without the necessity of holes being previously bored for the reception of the screw.

My invention is particularly adapted for use in securing rails in position in railway track service and to take the place of the ordinary railway spike. The. experiments conducted have demonstrated that a barbed screw of the type shown will require approximately seventeen thousand pounds pulling force to remove the screw from the ordinary cross tie when driven into position, whereas, the usual railway spike, depending upon the 'kind of wood into which it is driven, will have approximately a resisting strength of endwise withdrawal of about a thousand pounds. One of the problems in railway- 1931. Serial N0. 588,199.

require constant attention and constant inspection.

I am aware that screw spikes have been used for this purpose but they have been provided with a blunt end and in introducing them, it has been necessary to bore holes for the screws, the spikes bein driven in with heav sledges which resu ted in the breaking own of the wood fibers so that in appearance the spike is set pro erly in the tie but actually is not engaging t e wood fibers ,in order to withstand the enor,mous pulling strain that must be resisted.

Another important object of my invention is the provision of a particular type of single thread which is very effective in permitting the spike to be driven into the woodand which will worm its way in by a revolvin movement, thus cutting a path throng the fibers of the wood and not breaking them down and in order to carry out my invention, the single thread is so cut that the sides thereof or outer faces are inclined away from the point throughout their length toward the shank of the stem of the screw, the thread being continuous from the tip of the point to the shank of the stem and terminating at its leading edge in a cutting edge which, due to the pitch of the thread is sitioned at such an anglethat when driving force is applied to the screw, the cutting edge will be cammed into the wood and will not be driven (downwardly direct but will start the revolving movement of the screw due to the sharp edge or cutting edge at theleading edge of the screw.

Another and further object of my invention is the provision of abarbed screw which can be easily and cheaply manufactured and rapidly produced and which is easily positioned and has a high degree of efiiciency in service.

Changes and variations may be made in the construction shown and described with out departing from the principles of the invention or sacrificing its chief advantages; hence such invention is not to be confined to the structures shown in the accompanying drawing:

Figure 1 is a view in elevation of a screw spike constructed in accordance with my invention, a single thread being illustrated in connection with the spike.

Figure 2 is a view similar to Figure 1 showing a screw spike having formed thereon a double thread.

Figure 3 is an end view of the threaded end of the screw illustrated in Figure 2.

Figure 4 is an enlarged view of a screw s ike having a difierent form of head than t at illustrated in connection with the screw spike shown in Figure 1 and also having formed thereon a coarser thread terminating in my improved point.

Figure 5 is an end view of the screw spike shown in Figure 4, and

Figure 6 is an enlarged view of the leading end of the screw spike illustrated in Figure 4 showing the position of the cutting edge and leading point.

Referring to the drawingin detail, and in particular to Figures 1, 4 and 5 and 6, numeral 5 indicates the body and 6 the threaded portion of a single thread" barbed drive screw constructed in accordance with my invention, a nut head 7 being provided on the screw illustrated in Figure 1 throu h the medium of which the screw may be wit drawn, in this figure, the screw thread 6 being provided on the body 5 less than half the len th thereof.

In igure 4, the thread 6 which is of the single type, extends more than half the length of the body 5 of the screw but either form may be used de ending upon the conditions under which t e drive screw is to be employed. In the screw illustrated in Figure 4, the upper end is provided with a square head 8 and a circular shoulder portion 9, it being understood that the head may be varied de ending upon the conditions under which e screw is employed.

The screw thread 6 may have a pitch that will assist in its rotative movement when it is driven into wood, the angle of the pitch having been found to be about degrees although this can be decreased or increased within certain limits to be found most efficient in operation. Another feature of my screw thread is the fact that the outer face '10 thereof'is thrown back from the point at an angle throughout its length toward the body 5, the angle of this throw-back being such that the thread is assisted in its movement into the wood when driven and to ef- 4 fectively accomplish its turning movement so that breaking down of the wood fibers is eliminated and the thread is thoroughly embedded in the wood, the upper edges thereof as indicated at 11, being cut horizontally or downwardly and inwardly toward the median line of the screw to provide a barb which will resist the endwise withdrawal of the screw without turning the same. An important feature of my invention and perhaps the most important, is the termination of the single thread at the leading end of the screw as illustrated in Figure 6 and this is so terminated that the shelf or shoulder 11 forms a lip which provides a cutting edge or side 12, the upper edge of which 13 terminates at the bottom end or point of the screw shank. The cutting edge or side 12 is disposed at an angle relatively to the median line of the screw and the material of the shank beneath the shoulder 11 and indicated the screw is started into the wood and this revolving movement is further assisted and compelled by reason of the angle of the face 10 of the thread away from the point of the shank.

The outer end of the cutting edge 12 forms a piercin point 15 and. when this point is positione at the point on the wood in which the screw is to be driven, it will immediately pierce the wood to a depth equal to the cutting edge 12 and a drive blow on the screw will cause the screw to start rotating due to the feature, as above explained. This leading point will keep the screw in vertical alignment durin its driving movement into the wood and t e throw-back angle of the face 10 of the thread together with the action of the cam surface 14 at the leading end of the screw thread will cause a continuous rotation thereof and a worming of the thread into the wood so that it will be effectively seated therein, will not break down the fibers of the wood but will cause them to overlap the upper, barbed ed e or shelf 11 of the thread and effectively old the screw in position.

In Figure 2 there is illustrated a screw spike 16, the body portion 17 is threaded as at 18 with a double thread screw, one of the threads of which may merge into the body of the screw while the other may terminate as is illustrated in Figure 6, so that the same My invention is not to be restricted to the precise details of construction shown since various changes and modifications may be made therein without departing from the scope of the invention or sacrificing the advantages derived from its use.

' What I claim is As a new article of manufacture, a screw element havin a cylindrical body terminating at one en in a tapered point, a thread formed on the body extending to and throu hout said ta red point, said thread provi ing a shoul ered upper surface terminating at the tapered point of the body in an entering lip, one edge of said lip comprising a cutting side disposed at an angle downwardly from said tapered point and the other edge of said lip being disposed at said tapered point and in the median line of said 20 body.

In testimony whereof I aflix m ature.

JOHN A. AREN L. s.] 

